From mboxrd@z Thu Jan  1 00:00:00 1970
From: Thomas Gleixner <tglx@linutronix.de>
Subject: Re: Arches that don't support PREEMPT
Date: Tue, 19 Sep 2023 17:17:23 +0200
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To: Anton Ivanov <anton.ivanov@cambridgegreys.com>, Peter Zijlstra <peterz@infradead.org>, John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
Cc: Matthew Wilcox <willy@infradead.org>, Linus Torvalds <torvalds@linux-foundation.org>, Ankur Arora <ankur.a.arora@oracle.com>, linux-kernel@vger.kernel.org, linux-mm@kvack.org, x86@kernel.org, akpm@linux-foundation.org, luto@kernel.org, bp@alien8.de, dave.hansen@linux.intel.com, hpa@zytor.com, mingo@redhat.com, juri.lelli@redhat.com, vincent.guittot@linaro.org, mgorman@suse.de, rostedt@goodmis.org, jon.grimm@amd.com, bharata@amd.com, raghavendra.kt@amd.com, boris.ostrovsky@oracle.com, konrad.wilk@oracle.com, jgross@suse.com, andrew.cooper3@citrix.com, Geert Uytterhoeven <geert@linux-m68k.org>, linux-m68k@lists.linux-m68k.org, Richard Weinberger <richard@nod.at>, Johannes Berg <johannes@sipsolutions.net>, linux-um@lists.infradead.org, Brian Cain <bcain@quicinc.com>, l

On Tue, Sep 19 2023 at 15:21, Anton Ivanov wrote:
> On 19/09/2023 14:42, Peter Zijlstra wrote:
>> If you're working on one of them, then surely it's a simple matter of
>> working on adding CONFIG_PREEMPT support :-)
>
> In the case of UML adding preempt will be quite difficult. I looked at
> this a few years back.

What's so difficult about it?

Thanks,

        tglx